Metal impregnated fiber article and process of making same



Patented May 3, 1932 UNITED STATES PATENT OFFICE I MEYRL FROST, OFCAPAC, MICHIGAN, ASSIGNOR TO DUROWOOD INDUSTRIES IN- CORPORATE-D 0FDETROIT, 0F DETROIT, MICHIGAN, A CORPORATION OF MICHIGAN METALIMPREGNATED FIBER ARTICLE AND PROCESS OF MAKING SAME No Drawing.

This invention relates to metal impregnated fiber articles and toprocesses for manufacturing fiber articles impregnated with a metallicsubstance or metal-like substance.

An object of this invention is a fiber article of any form or shape,impregnated with a metallic material, whereby the article, tho made offiber, has certain of the characteristics of similar articles made ofmetal or covered with sheets of metal, etc.

Another object is a novel process formaking fiber articles havingcertain metallic properties, the process including as one of its'steps,the step of impregnating the articles with a metallic material.

Still further objects will readily occur to those skilled in the artupon reference to the followin description of the invention.

The article embodying the invention is a shaped fibrous articleimpregnated with a metallic substance.

The fibrous article, per se, may be composed of any suitable fibrousorganic material, such as wood pulp, paper pulp, rag pulp, etc., mixedwith a suitable adhesive or binder, and is in the nature of adehydrated, form-retaining mass, of any desired shape.

The metallic substance used for impregnating the article may be copper,bronze, brass, metallic lead, metallic tin, etc. 'It'may also be one ormore of the so-called low melting point alloys involving lead, tin,bismuth, cadmium, etc. It may also be of glass, which, tho not a metal,will be considered as a metallic material, since, as far as theinvention is concerned, glass has the protecting properties of themetals above described. Other substances, not specifically named above,may also be used as the metallic substance of the invention.

When the metallic substance selected as the impregnating substancepossesses a comparatively high melting point, that is to say a meltingpoint much higher than the charring point of the fibrous material, thelatter may be so treated as to include as a constituent, a fire resistinorfire proofing material whose presence raises the charring point of thefibrous material, giving to the article to be impregnated, the propertyof not charring tho Application filed March 16, 1931.

Serial No. 523,199.

it is immersed in the molten metal, then at a comparatively hightemperature.

The article embodying the invention, tho constituted of fibrous organicmaterial is found to possess certain desirable properties, due to itsmetallic impregnation, one of them being its exposure resistingcharacteristic.

The processes of manufacturing articles such as those above described,in general, include two major steps: (a) shaping the fibrous article and(b) impregnating the latter with a metallic substance. Variousrefinements of the simple process have been discovered and these,together with the simple process will now be described.

In shaping the fibrous article, a plastic, Wet, mass of the fibrous pulpis used, and the latter is then shaped, in molds, rolls, presses, or thelike, under a pressure which may be in the neighborhood of from onehundred to several hundred pounds per square inch, this pressure beingsufiicient to squeeze the water out of the mass and to dehydrate it. Theresultant article is a fibrous, shaped and partially dried article andwhen completely dried is ready for the next step, impregnation.

1n impregnating the article, the latter is subjected to the influence ofa partial vacuum which serves to draw air from the article itself. Thenwhile the article is still in the exhausted condition, it is immersed ina bath of molten metallic substance, the latter having a melting pointnot a great deal above, the charring point of the article.

.While the article is so immersed, the partial vacuum is relieved, andthe article is then placed under a pressure of one or more atmospheres,as desired. The pressure thus applied forces the substance into theouter portion of the article, and when the latter is re moved from itsbath, it will be found to be impregnated with an amount of thesubstance.

The degree of impregnation may be controlled readily, since it is knownto depend upon the nature of the materials used, upon the degree ofexhaustion prior to immersion, upon the duration of the period ofimmersion, and upon the degree of pressure subsequent to immersion.

fibrous material, that the latter will char when immersed in the moltenmetallic substance. Under these conditions, it becomes desirable toprepare the article, before inimersion, in such a Way that its charringpoint will be raised, and the following has been found to be aneffective mode of accom dishing this result.

Into the pulpy, plastic mass of fibrous ma terial, is introduced, bybeating, stirring, etc, an amount of a fire resistant material, such asasbestos, calcium carbonate, calcium chloride, alum, limestone, etc.,these being of the mineral fire resistlng group. The plastic mixture,now including the fibrous material and the fire resistant material, isthen shaped and dehydrated, just as was shaped and dehydrated theplastic mass of fibrous material, in the manner above described. Theselection of the proper mineral fire resistant material, and the amountused, depends upon the nature of the fibrous material, the metallicsubstance, etc. and the particulars of this step may befound uponsuitable trial.

Now having described the invention and the preferred embodiment thereof,it is to be understood that the said invention is to be limited, not tothe specific details herein set forth, but only by the scope of theclaims which follow:

lVhat I claim is:

1. The method of producing an'article in predetermined shape or form andhaving exposure resistant characteristics which comprises shaping orforming the said article under pressure from a pulp of fibrous material,drying the shaped article, and then superficially impregnating saidarticle with a metal-like material.

2. The method of producing an article in predetermined shape or form andhaving exposure resistant characteristics which comprises shaping orforming the said article under pressure, drying the shaped article,andthen superficially impregnating said article with a metal-likematerial by evacuating the air from said irticle and immersing in aprises shaping or forming said articles from.

organic fibrous materials and superficially impregnating said articleswith metal-like material of a melting point not substantially M greaterthan the char point of the articles.

4. The process Which comprises producing a fluent pulp of fibrousmaterial and water containing adhesive, forming said pulp into asuitable shape and expressing the water therefrom under moderatepressure, drying the shape, and superficially impregnating said articlewith a metallic substance.

a. fluent pulp of fibrous material and water containing adhesive,forming said pulp into a suitable shape and expressing the watertherefrom under moderate pressure, drying.

the. shape, and providing said shape witha coating and superficiallyimpregnating layer of a metallic substance. 7

In testimony whereof I sign this specification.

MEYRL M. raos'r.

